The present invention relates to a sheet cutter that cuts edges of sheets to true up them for a bundle of sheets after operations of center-stapling processing, center-folding processing and bookbinding processing, and to an image forming apparatus equipped with the sheet cutter.
There have been known TOKKAIHEI Nos. 6-72064, 7-187479 and 8-192951 as a sheet finisher that conducts center-stapling processing for a bundle of sheets in which one set is composed of a plurality of sheets.
Further, there have been proposed TOKKAIHEI Nos. 10-148983 and 10-167562 as a sheet finisher that makes twofold processing possible.
There is available a sheet cutter that cuts edges of sheets to true up them for a bundle of sheets after operations of center-stapling processing, center-folding processing and bookbinding processing. Further, in recent years, there has been proposed an sheet finisher equipped with a sheet cutter wherein edges of sheets are cut by the sheet cutter to true up the sheets after operations of center-stapling processing, center-folding processing and bookbinding processing are conducted like a weekly magazine by the sheet finisher for a bundle of sheets on which images are recorded by an image forming apparatus such as a copying machine, a printer and a compound machine wherein the copying machine and the printer are combined.
(First Problem)
With regard to a booklet stand of a conventional booklet storing means which stores a plurality of booklets which have been cut and are stacked, there are used a booklet stand of a bucket type and that of a conveyer type.
The booklet storing means of a bucket type is one wherein booklets which have been cut are ejected as they are and are stacked on a sheet ejection tray that is fixed at the lower portion on the side of a sheet cutter. On the booklet storing means of this type, storing capacity for booklets is small, and workability for taking out a plurality of booklets collectively is poor.
The booklet storing means of a conveyer type is one that is equipped with a sheet ejection belt that is arranged almost horizontally at the lower portion on the side a sheet cutter, and is rotated. A booklet which has been cut is placed on the rotating sheet ejection belt to be moved, and a succeeding booklet is placed to be overlapped partially with the preceding booklet on the sheet ejection belt to be moved. The booklet storing means of this type requires a long and large sheet ejection belt and has small capacity for stacked booklets.
(Second Problem)
The booklet which has been subjected to center-stapling processing and twofold processing is in a shape in which a portion in the vicinity of a folded section is swelled. After flattening the booklet by pressing the top face including the portion in the vicinity of the folded portion of the booklet with a pressure plate of a pressing means, prior to cutting processing for truing up edges of a booklet, an upper blade of a cutting means is lowered so that the upper blade and a lower blade cut jointly edges of the booklet to true up the edges.
On the conventional sheet cutter, an ascent and descent means for lifting and lowering the pressure plate and a driving means are arranged to be fixed on the upper portion of a booklet conveyance path. Accordingly, when defective conveyance for a booklet is caused in the booklet conveyance path, it is difficult to take out the booklet in the defective conveyance, because of upper mechanisms such as the ascent and descent means in the booklet conveyance path and the driving means.
Further, it is difficult to make the space over the booklet conveyance path to be broad and taking out of the booklet in the defective conveyance is difficult accordingly, because the pressure plate only moves within a range through which a booklet with a maximum thickness can pass.
(Third Problem)
An amount of a protrusion on the edge (an end edge portion) of the trailing edge in the conveyance direction of the booklet which has been subjected to center-stapling processing and twofold processing varies depending on the number of sheets in the booklet. Namely, an edge of the innermost sheet forming the booklet is more protruded than that of the outermost sheet. The more the number of sheets of the booklet is, the greater an amount of protrusion is. Therefore, if cutting is conducted at the fixed position, the edges fail to be trued up by defective cutting. In addition, if cutting is conducted more than needed, the size of the finished booklet turns out to be too small.
(Fourth Problem)
When the front door of the sheet cutter is opened, operations of the driving means of the sheet cutter are stopped, but, it sometimes happens that a user accidentally touches its fingertip to a sharp upper cutting blade and a lower cutting blade of the cutting means in suspension to be injured. In the invention, there is provided a safety device which always prevents that a fingertip of a user is brought into contact to be injured.
(Fifth Problem)
In the sheet cutter of a type wherein a booklet storing section that stores the booklet which has been subjected to edge cutting processing is protruded to be out of an enclosure of a sheet cutter main body, it sometimes happens that a user accidentally stumbles against the protruded sheet storing section to be injured. It further happens that the sheet storing section is hit by a moving object, and damages or troubles are caused. In the invention, there is provided a safety device which prevents that a user hits the sheet cutter to be injured.
(Sixth Problem)
A booklet which has been subjected to center-stapling processing and twofold processing by the sheet finisher is usually ejected from an ejection section located at the lower portion of the sheet finisher. This sheet finisher is provided with an ascending and descending sheet ejection tray capable of storing a large number of sheets which have neither been subjected to center-stapling processing nor been subjected to twofold processing. Under the condition that a sheet cutter is connected to the sheet finisher, if a clearance between a bottom of ascending and descending sheet ejection tray and an upper part of an outer wall of the sheet cutter is small when the ascending and descending sheet ejection tray is lowered to its lower limit position, it happens that a user""s hand is caught by the clearance between the ascending and descending sheet ejection tray and the upper part of an outer wall of the sheet cutter to be injured, or objects are caught by the clearance, resulting in occurrence of damages and troubles. In the invention, there is provided a safety device which prevents that a user is injured when driving the sheet finisher.
The first object of the invention is to attain an improvement of workability of a sheet storing section on which finished booklets are ejected and stacked after edges of a bundle of sheets subjected to center-stapling processing and twofold processing are cut, and to attain an increase of a storing capacity for booklets and miniaturization of the sheet cutter.
The second object of the invention to solve the second problem stated above is to attain an improvement of workability in clearance of jammed booklet (jam clearance) in a cutting means and a conveyance means.
The third object of the invention to solve the third problem stated above is to make the optimum cutting corresponding to the number of sheets of a booklet to be folded double to be possible.
The fourth object of the invention is to provide a safety device so that a user may not be injured in the course of operating the sheet cutter.
The first object stated above can be attained by the following structures each representing a sheet cutter of the invention.
Structure (1):
A sheet cutter for finishing a booklet by cutting, with a cutting means, edges of a bundle of sheets folded double, wherein it is possible to load booklets on a booklet stand of a booklet storing means that stores a plurality of booklets which have been subjected to cutting processing, by overlapping sheet faces, with a folded portion of each booklet facing upward.
Structure (2):
A sheet cutter for finishing a booklet by cutting, with a cutting means, edges of a bundle of sheets folded double, wherein there are provided a rotatable roller with a large diameter which is arranged at the downstream side in the sheet conveyance direction of the cutting means and deflects the booklet subjected to cutting processing to the vertical direction from a conveyance means in the cutting section to convey to a booklet storing means, a pinch roller that presses the booklet against the large diameter roller to convey and is capable of being driven to rotate, and a guide plate that deflects the booklet to the vertical direction from the conveyance means in the cutting section and guides the booklet to the interposing position between the large diameter roller and the pinch roller.
Structure (3):
A sheet cutter for finishing a booklet by cutting, with a cutting means, edges of a bundle of sheets folded double, wherein there are provided a booklet ejection opening through which a booklet subjected to cutting processing passes to a booklet storing means, a booklet stand of the booklet storing means that accepts the booklet from the booklet ejection opening so that the booklets are loaded to be overlapped in terms of sheet faces, with a folded portion of each booklet facing upward, a movable wall member that presses a sheet face of the booklet supported to stand upright on the booklet stand and reciprocates between the topside of the booklet stand and the booklet ejection opening, and a driving means that makes the movable wall member to reciprocate, wherein the movable wall member accepts the booklet that is usually loaded at the stop position on the booklet stand, then, retreats to the rear position of the booklet ejection opening each time a booklet subjected to cutting processing is conveyed to the booklet stand, and returns to the stop position while pressing the sheet face of the booklet to stand ready after the booklet finishes passing through the booklet ejection opening.
Structure (4):
A sheet cutter for finishing a booklet by cutting, with a cutting means, edges of a bundle of sheets folded double, wherein there are provided a booklet ejection opening through which a booklet subjected to cutting processing passes to a booklet storing means, a booklet stand of the booklet storing means that accepts the booklet from the booklet ejection opening so that the booklets are loaded to be overlapped in terms of sheet faces, with a folded portion of each booklet facing upward, a movable wall member that presses a sheet face of the booklet supported to stand upright on the booklet stand and reciprocates between the topside of the booklet stand and the booklet ejection opening, a partition member that is arranged to face a sheet face of the movable wall member and can move in the direction perpendicular to the booklet stand, and a driving means that makes the movable wall member and the partition member to reciprocate, wherein the movable wall member accepts the booklet that is usually loaded at the stop position on the booklet stand, then, retreats to the rear position of the booklet ejection opening each time a booklet subjected to cutting processing is conveyed to the booklet stand, and before the movable wall member retreats for accepting the booklet and the booklet ejection opening is opened, the partition member moves to the position where the end portion of the booklet is accepted in place of the movable wall member, and when the movable wall member moves to the stop position while pressing the sheet face of the booklet, the partition member starts moving to retreat so that the booklet stand may accept the booklet.
Structure (5):
A sheet cutter for finishing a booklet by cutting, with a cutting means, edges of a bundle of sheets folded double, wherein there are provided a booklet stand of a booklet storing means on which a plurality of booklets subjected to cutting processing are accepted and loaded to be overlapped in terms of sheet face with each folded portion facing upward, a movable pressure wall member that is supported to stand upright on the booklet stand and presses the sheet face of the booklet loaded on the booklet stand, and a coil-shaped constant load spring member composed of a long leaf spring that is coiled to urge the pressure wall member.
Structure (6):
A sheet cutter for finishing a booklet by cutting, with a cutting means, edges of a bundle of sheets folded double, wherein there are provided a booklet stand of a booklet storing means on which a plurality of booklets subjected to cutting processing are accepted and loaded to be overlapped in terms of sheet face with each folded portion facing upward, a movable wall member that is supported to stand upright on the booklet stand, presses the sheet face of the booklet loaded on the booklet stand and reciprocates on the booklet stand to support the sheet face of the booklet, and a movable pressure wall member that faces the movable wall member to press the sheet face of a booklet loaded on the booklet stand, and the pressure wall member is composed of a pressure wall face section that stands upright on the aforesaid booklet stand to be in parallel with a sheet supporting wall face of the opposing movable wall member to press the sheet face of the booklet and of an inclined surface section having an inclination angle in the direction wherein the upper part of the pressure wall face goes away from the sheet supporting wall face of the movable wall member.
Structure (7):
An image forming apparatus having therein an image forming means that forms an image on a sheet fed by a sheet feeding means according to image information, a sheet finisher equipped with a stapling means that conducts center-stapling for a bundle of sheets on which images are formed and with a folding means that conducts twofold processing for a bundle of sheets subjected to center-stapling processing, and a sheet cutter described in Structures (1)-(6) stated above, wherein edges of the bundle of sheets subjected to twofold processing and center-stapling are cut by the cutting means to finish a booklet.
The second and third objects mentioned above are attained by the following structures of the invention including sheet cutters.
Structure (8):
A sheet edge cutting method to finish a booklet by cutting edges of a booklet which has been center-stapled and folded double with a cutting means, wherein there is provided a pressing means capable of ascending and descending that presses and separates the top face of a booklet placed at a prescribed position on a conveyance member that conveys the booklet, and the pressing means is driven by a driving means arranged at the lower portion of the conveyance member to press a booklet placed on the conveyance member so that edges of the booklet may be cut and trued up by the cutting means.
Structure (9):
A sheet cutter to finish a booklet by cutting edges of a booklet which has been center-stapled and folded double with a cutting means, wherein there are provided a conveyance means to convey the booklet, a pressing means capable of ascending and descending that presses and separates the top face of a booklet placed on the conveyance means, a ascending and descending means that drives the pressing means to ascend and descend to press and release a top face of a booklet, and a driving means that drives the ascending and descending means, and the ascending and descending means and the driving means are arranged below the conveyance means.
Structure (10):
A sheet cutter to finish a booklet by cutting edges of a booklet which has been center-stapled and folded double with a cutting means, wherein there are provided a conveyance means to convey the booklet, a movable stopper that can move to be in parallel with the conveyance direction for the booklet, a positioning means that positions the movable stopper at a fixed position in accordance with a booklet size, and a control means that adjusts finely the position of the movable stopper from the prescribed position for each size of the booklet in accordance with the number of sheets of a booklet to be folded.
Structure (11):
An image forming apparatus having therein an image forming means that forms an image on a sheet fed by a sheet feeding means according to image information, a sheet finisher equipped with a stapling means that conducts center-stapling for a bundle of sheets on which images are formed and with a folding means that conducts twofold processing for a bundle of sheets subjected to center-stapling processing, and a sheet cutter described in Structures (9)-(10) stated above, wherein sheets on which images have been formed are subjected to center-stapling processing and twofold processing to form a booklet which is then pressed by a pressing means capable of ascending and descending, and edges of the booklet are cut by a cutting means so that the booklet is finished.
The fourth object mentioned above is attained by the following structures of the invention including sheet cutters.
Structure (12):
A sheet cutter to finish a booklet by cutting edges of a booklet which has been center-stapled and folded double with a cutting means, wherein, there is arranged a rotating means for conveying a booklet that prevents that a fingertip of an operator is brought into contact with an upper cutting blade and a lower cutting blade at each of the upstream side and the downstream side of a conveyance path for a booklet that passes through a gap between the upper cutting blade and the lower cutting blade both constituting the cutting means.
Structure (13):
A sheet cutter to finish a booklet by cutting edges of a booklet which has been center-stapled and folded double with a cutting means, wherein, there are provided a sheet cutter main body having therein a conveyance means that conveys the booklet, the cutting means and an ejection means that ejects the booklet subjected to cutting processing out of an apparatus, a booklet storing means that can store a large number of booklets which have been cut and ejected by the ejection means and is protruded out of a sheet cutter main body, and a protection member that is formed to surround the outer circumference of the booklet storing means and is fixed on the sheet cutter main body.
Structure (14):
An image forming apparatus equipped with a sheet finisher having therein a center-stapling means that staples the sheets ejected out of an image forming apparatus main body at their central portion in the conveyance direction and a folding means that folds the sheets center-stapled by the center-stapling means double and with a sheet cutter that is connected to a sheet ejection section of the sheet finisher, conveys with a conveyance means the booklet center-stapled and folded double, and finishes a booklet by cutting edges of a booklet with a cutting means, wherein the sheet finisher has an ascending and descending sheet ejection tray capable of storing a large number of sheets to be ejected, and a prescribed space section is secured between a bottom portion of the ascending and descending sheet ejection tray that has reached its lowermost position and an upper portion of the outer wall of a casing in the vicinity of an inlet of the conveyance means of the sheet cutter.